This invention relates to a method and apparatus for embossing or imprinting a selected indicia on the surface of a miniature turned part such as, for example, a connector pin used in a multi-pin electrical connector. In general, the present invention is usable in connection with turned parts which are of the order of one quarter inch diameter or less such as electrical connector pins, small toggle switch levers, miniature pins or the like. Frequently, manufacturers of products which embody such parts may wish to mark the individual parts for a variety of reasons, sometimes to identify the manufacturer of the part or for other part identification purposes.
Usually, such miniature parts are turned in complex precision machinery having numerous tools and work-holding devices which may be operated in a particular sequence and manner to manufacture the particular part. When it is desired to mark such a miniature part with a selected indicia, it has been a typical practice first to manufacture the part in the machinery and then, in a secondary and subsequent operation, pass the part through a separate stamping device which imprints the indicia on the part. This secondary operation adds significantly to the handling and cost of the part which, in the usual massive volumes in which such parts are made, can be very costly.
In accordance with the present invention, the part is marked or imprinted with the selected indicia while the part is being manufactured in the precision turning machinery. The present invention, thus, completely avoids any secondary stamping operation with a resultant and substantial economic saving. More specifically, at some point during the automatic manufacture of the part in the precision turning machinery, the part is gripped securely, usually by a collet. The collet may be mounted on a turret which is movable to feed or advance the workpiece to a subsequent tool in the machine to perform a subsequent operation. In accordance with the present invention, the part is marked directly by the collet which is provided with an embossing stamp formed directly on the work-clamping surface of the collet. Thus, when the collet grips the part during the normal sequence operation of the turning machine, that automatically marks the part and completely avoids the secondary stamping operation.
It is among the general objects of the invention to provide an improved method and apparatus for marking miniature turned parts with a selected indicia.
Another object of the invention is to provide a method and apparatus for marking such parts which completely avoids the necessity for a secondary stamping or imprinting operation.
Another object of the invention is to provide a method and apparatus of the type described which results in substantially lower manufacturing costs for the part.
Still another object of the invention is to provide a method and apparatus for imprinting or embossing a miniature turned part directly in the turning machinery and simultaneously during manufacture of the part.